Combination of a sealable can adapted to be evacuated and a vacuum pump

Abstract: A sealable can which may be evacuated of air comprises can body (1), a cap unit (2) and a vacuum pump (3), the cap unit being fitted onto the can body, the vacuum pump being placed on the cap unit to pump the air from the can body so that the can body becomes evacuated and sealed tightly by the can unit to preserve food kept therein good and fresh for a long period of time.

Description: Background of the Invention Nowadays containers for preserving food generally comprise a container and cap for the container. Though food kept in the container is preserved by the cap, but some air is also kept in the container when the cap is fitted to the container, in spite of air being kept out of the container by the cap. So the food in the container can gradually deteriorate in its quality after a long period of time due to the air remaining therein. EP 0378866 relates to a vacuum container having an indication member for indicating a pressure difference between the interior and exterior of the container. A one-way valve which opens laterally is provided in the cover of the container to allow air to be removed therefrom using the valve described in EP 0234607. However, this container does not consider the formation of a satisfactory seal between the container and its exterior and the vacuum pump for evacuation of the air. DE 3345599 describes a type of non-return valve having a valve flap which is mounted on a valve housing and covering through apertures. Summary of the Invention According to the invention there is provided a combination of a sealable can for preserving food and a vacuum pump by means of which the can can be evacuated so that the food kept therein can be preserved with its quality good and fresh for a long period of time. A combination of a sealable can which may be evacuated and a vacuum pump in accordance with the present invention comprises a cylindrical can body, a cap unit fittable on said can body, and a vacuum pump, being characterised in that the cap unit has a sealing cap body, having a central upper recess a central through hole in said upper recess, a plurality of air holes spaced around said central through hole, a downwardly projecting annular wall engaging a small bottom cap, a projecting outer circumferential curved edge, a first annular downwardly projecting wall extending from said curved edge, a second annular downwardly projecting wall of a smaller diameter than said first annular wall, an annular groove defined by said first and second annular walls for an annular gasket to engage in; the small bottom cap fitting around said downwardly projecting annular wall, and having air holes; the annular gasket fitting in said annular groove of said sealing cap body for blocking through flow of air; an air valve in the recess of said sealing cap body, closing said air holes, and having a mushroom-shaped projection extending downwards to pass through said central hole of said sealing cap body to keep said valve in place, and upwardly sloping projections for pulling said air valve; a small upper cap covering said air valve, having a circumferential downwardly sloping surface and opposing slots for the two upwardly sloping projections to protrude upwardly therethrough and the vacuum pump independently provided and to be placed on the top of said cap unit for pumping the air from said can body; the vacuum pump having a stationary cylinder having a central passageway for a pull cylinder to fit and move therein up and down and a stop annular edge for stopping the pull cylinder and a flange around the bottom fitting in an annular groove of a socket; the pull cylinder having an annular groove in in a lower end portion, opposite air holes in said annular groove, an annular gasket engaging said annular groove; and a handle having a cylindrical portion with two lateral curved portions fixed firmly on the top of said pull cylinder above the stationary cylinder to pull said pull cylinder for pumping out the air in said body, and having an inner groove and an inner sloping edge below said groove; whereby said vacuum pump can be placed on the top of said cap unit wherein an engaging edge of the socket is tightly placed on the recess of the sealing cap body and said pull cylinder is pulled up and down in said stationary cylinder to draw out the air from said can body forming a vacuum so that internal and atmospheric pressure difference causes said valve of the cap unit to close tightly said air holes in said sealed cap body, thereby preserving food therein for a long period of time. Brief Description of Drawings The invention will now be further described, by way of example only, with reference to the accompanying drawings, in which:- Figure 1 is an exploded perspective view of a sealable can which can be evacuated of air; Figure 2 is a cross-sectional view of a sealing cap body of a cap unit of the sealable can of Figure 1; Figure 3 is an exploded perspective view of a vacuum pump of the present invention; Figure 4 is a half cross-sectional view of a sealable can of the present invention; Figure 5 is a cross-sectional view of the sealable can and the vacuum pump of the present invention, showing air flow direction in pumping air from the sealable can; Figure 6 is a cross-sectional view of the vacuum pump placed on the sealable can in the present invention, showing air flow direction when the pump is pressed down; Figure 7 is a cross-sectional view of the sealed can in the present invention showing air entering into the can body when the air valve is pulled open. Detailed Description of the Invention Referring to the accompanying drawings, a sealable can which may be evacuated of air in accordance with the present invention, as shown in Figs. 1, 2, 3, comprises a can body 1, a cap unit 2, and a vacuum pump 3 independently provided to pump the air from the can body 1. The can body 1 is cylindrical and covered with the cap unit 2. The cap unit 2 has a sealing cap body 20, a small bottom cap 21 with two air holes 210, 210 fitting around an annular downwardly projecting wall 203, an annular gasket 22, an air valve 23 and a small upper cap 24 combined together. The sealing cap body 20 has a central recess 200, a central through hole 201 in the central recess 200, four air holes 202 spaced apart around the central hole 201, and annular downwardly projecting wall 203 defining a round hollow space, an outer circumferential edge 204, an annular wall 206 of a smaller diameter than the wall 205 extending down from the lower surface of the cap body 20 and an annular groove 207 defined by the two walls 205, 206 as shown in Fig. 2 to receive the annular gasket 22 therein. The annular gasket 22 is made of a soil elastic material having an annular bulging edge 220 and fitting in the annular groove 207 to prevent air from passing therethrough. The air valve 23 sits in the recess 200 of the sealing cap body 20, made of a soil rubber and having two sloping projections 231, 231 and a mushroom-shaped projection 230 extending down from the center to pass through the central hole 201 of the sealing cap body 20. The small upper cap 24 covers the air valve 23, having a swelled upper surface, an annular downwardly sloping surface 240 and two opposite slots 241, 242 for the two projections 231, 231 of the air valve 23 to pass upwards therethrough. The air vacuum pump 3 shown in Fig. 3, comprises a cylinder 30, an annular socket 31, a pulling cylinder 32, an annular gasket 33 and a handle 34 combined together. The cylinder 30 has a central passageway 300, a stop edge 301 at the top of the cylinder 30, a flange 302 at the bottom to engage the annular socket 31, which has an inner annular groove 310 and an engaging edge 311 at bottom. The pull cylinder 32 fits in the passageway 300 of the cylinder 30. The pull cylinder 32 has an annular projection 320, an air exit hole 321 below the annular projection 320, an annular groove 322 in the bottom for the gasket 33 to engage with and two opposite air inlet holes 323, 323 in the annular groove 322. The handle 34 is provided to fit around the top of the pull cylinder 32, having two curved plates extending from two opposite sides, an inner annular groove 340 and a sloping edge 341 under the groove 340. In assembling, as shown in Figs. 1, 3 and 4 first the small bottom cap 21 is fitted around the downwardly projecting wall 203 of the sealing cap body 20, and next, the annular gasket 22 is inserted in the annular groove 207, and the downward projection 230 of the air valve 23 is forced to pass through the central hole 201 of the sealing cap body 20, with the air valve 23 closing the four air holes 202. After that the air valve 23 is covered by the small upper cap 24 with the two projections 231, 232 protruding up through the two slots 241, 242. Then the small upper cap 24 is combined in the central recess 200 of the sealing cap body 20 by means of high frequency welding process. The assembly of the cap unit 2 is finished. Then, the vacuum pump 3 is to be assembled, by engaging the gasket 33 around the groove 322 of the pull cylinder 32, pushing the pull cylinder 32 in the passageway 300 of the cylinder 30 from below, engaging the annular socket 31 with the bottom of the cylinder 30, with the flange 302 fitting in the inner groove 310 of the socket 31, fitting the handle 34 around the top of the pull cylinder 32, with the inner groove 340 engaging the annular projection 320. Then assembly of the vacuum pump 3 is finished. In use, food to be preserved is placed in the can body 1, and then the cap unit 2 is fitted onto the top of the can body 1. Next, as shown in Fig. 4, the engaging edge 311 of the annular socket 31 of the vacuum pump 3 is tightly placed on the central recess 200 of the sealing cap body 20. Then the pull cylinder 32 of the vacuum pump 3 is pulled up as shown in Fig. 5 to evacuate the air in the cap body 1 from the cap unit 2. The air in the can body 1 is drawn through the two air holes 210 of the small cap 21, then through the four air holes 202, through the space between the air valve 23 and the central recess 200 of the sealing cap body 20 and through the two slots 241, 242 to flow into the cylinder 30. Meanwhile, the bottom of the pull cylinder 31 is stopped by the stop edge 301 of the cylinder 30, with the gasket 33 tightly fitting in the groove 322 and closely blocking the two air holes 323. When the pull cylinder 32 is pushed down to pump out the air in the body 1, as shown in Fig. 6, the gasket 33 is pushed upward, forcing the air in the cylinder 30 pumped out of the can body 1 to flow through the gap between the cylinder 30 and the pull cylinder 32 and through the two air holes 323 into the pull cylinder 32 to be exhausted out of the air exit 321 in the pull cylinder 32. Thus, the air in the can body 21 is pumped out by the vacuum pump 3, to produce a vacuum. The annular gasket 22 of the sealing cap body 20 is in tight contact around the top of the can body 1 because of the pressure difference between the interior and the exterior of the can body 1, preventing air from flowing into the can body. In addition, the four air holes 202 in the recess 200 of the sealing cap body 20 are tightly closed by the air valve 23, blocking open air from flowing through to keep the can body 1 in vacuum condition and preserving the food therein good and fresh for a long period of time. If the food in the can body 1 is to be removed as shown in Fig. 7, any of the two sloping projections 231, 231 of the air valve 23 protruding out of the two slots 241, 242 of the small upper cap 24 is moved inwards, letting a gap formed between the air valve 23 and the recess 200 of the sealing cap body 20 so as to let air flow through the two lots 241, 242, the four air holes 202 and the air holes 210 into the can body 1 until the pressure in the can body 1 becomes equal to that of the outside atmosphere. Then the cap unit 2 can be taken off the can body 1 and the food therein can be removed.

Claims: A combination of a sealable can and a vacuum pump therefor comprising a cylindrical can body (1); a cap unit (2) fittable on said can body (1), and a vacuum pump (3), characterised in that the cap unit has a sealing cap body (20) having a central upper recess (200) a central through hole (201) in said upper recess (200), a plurality of air holes (202) spaced around said central through hole (201), a downwardly projecting annular wall (203) engaging a small bottom cap (21), a projecting outer circumferential curved edge (204), a first annular downwardly projecting wall (205) extending from said curved edge (204), a second annular downwardly projecting wall (206) of a smaller diameter than said first annular wall (205), an annular groove (207) defined by said first and second annular walls (205, 206) for an annular gasket (22) to engage in; the small bottom cap (21) fitting around said downwardly projecting annular wall (203), and having air holes (210); the annular gasket (22) fitting in said annular groove (207) of said sealing cap body (20) for blocking through flow of air; an air valve (23) in the recess (200) of said sealing cap body (20), closing said air holes (210), and having a mushroom-shaped projection (230) extending downwards to pass through said central hole (201) of said sealing cap body (20) to keep said valve (23) in place, and upwardly sloping projections (231) for pulling said air valve (23); a small upper cap (24) covering said air valve (23), having a circumferential downwardly sloping surface (240) and opposing slots (241, 242) for the two upwardly sloping projections (231) to protrude upwardly therethrough and the vacuum pump (3) independently provided and to be placed on the top of said cap unit (2) for pumping the air from said can body (1); the vacuum pump (3) having a stationary cylinder (30) having a central passageway (300) for a pull cylinder (32) to fit and move therein up and down and a stop annular edge (301) for stopping the pull cylinder (32) and a flange (302) around the bottom fitting in an annular groove (310) of a socket (31); the pull cylinder (32) having an annular groove (322) in a lower end portion, opposite air holes (323) in said annular groove (322), an annular gasket (33) engaging said annular groove (322); and a handle (34) having a cylindrical portion with two lateral curved portions fixed firmly on the top of said pull cylinder (32) above the stationary cylinder (30) to pull said pull cylinder (32) for pumping out the air in said body (1), and having an inner groove (340) and an inner sloping edge (341) below said groove; whereby said vacuum pump (3) can be placed on the top of said cap unit (2) wherein an engaging edge (311) of the socket (31) is tightly placed on the recess (200) of the sealing cap body (20) and said pull cylinder (32) is pulled up and down in said stationary cylinder (30) to draw out the air from said can body (1) forming a vacuum so that internal and atmospheric pressure difference causes said air valve (23) of the cap unit (2) to close tightly said air holes (210) in said sealed cap body (20), thereby preserving food therein for a long period of time.

Inventors: YANG HENG-TE, YANG, HENG-TE
Applicants: YANG HENG TE, YANG, HENG-TE
Application year: 1994
Main classification: B65D81
IPC codes: B65D81, F04B33